Masaki Ichiro, Yonemitsu Yoshikazu, Yamashita Akihisa, Sata Shihoko, Tanii Mitsugu, Komori Kimihiro, Nakagawa Kazunori, Hou Xiaogang, Nagai Yoshiyuki, Hasegawa Mamoru, Sugimachi Keizo, Sueishi Katsuo
Department of Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Circ Res. 2002 May 17;90(9):966-73. doi: 10.1161/01.res.0000019540.41697.60.
Recent studies suggest the possible therapeutic effect of intramuscular vascular endothelial growth factor (VEGF) gene transfer in individuals with critical limb ischemia. Little information, however, is available regarding (1) the required expression level of VEGF for therapeutic effect, (2) the related expression of endogenous angiogenic factors, including fibroblast growth factor-2 (FGF-2), and (3) the related adverse effects due to overexpression of VEGF. To address these issues, we tested effects of overexpression of VEGF165 using recombinant Sendai virus (SeV), as directly compared with FGF-2 gene transfer. Intramuscular injection of SeV strongly boosted FGF-2, resulting in significant therapeutic effects for limb salvage with increased blood perfusion associated with enhanced endogenous VEGF expression in murine models of critical limb ischemia. In contrast, VEGF165 overexpression, 5-times higher than that of baseline on day 1, also strongly evoked endogenous VEGF in muscles, resulting in an accelerated limb amputation without recovery of blood perfusion. Interestingly, viable skeletal muscles of either VEGF165- or FGF-2-treated ischemic limbs showed similar platelet-endothelial cell adhesion molecule-1-positive vessel densities. Maturation of newly formed vessels suggested by smooth muscle cell actin-positive cell lining, however, was significantly disturbed in muscles with VEGF. Further, therapeutic effects of FGF-2 were completely diminished by anti-VEGF neutralizing antibody in vivo, thus indicating that endogenous VEGF does contribute to the effect of FGF-2. These results suggest that VEGF is necessary, but should be delicately regulated to lower expression to treat ischemic limb. The therapeutic effect of FGF-2, associated with the harmonized angiogenic effects seen with endogenous VEGF, provides important insights into therapeutic angiogenesis.
近期研究表明，肌肉注射血管内皮生长因子（VEGF）基因转移对严重肢体缺血患者可能具有治疗作用。然而，关于以下方面的信息却很少：（1）治疗效果所需的VEGF表达水平；（2）包括成纤维细胞生长因子-2（FGF-2）在内的内源性血管生成因子的相关表达；（3）VEGF过表达引起的相关不良反应。为了解决这些问题，我们使用重组仙台病毒（SeV）测试了VEGF165过表达的效果，并与FGF-2基因转移进行直接比较。在严重肢体缺血小鼠模型中，肌肉注射SeV可强烈促进FGF-2表达，从而产生显著的肢体挽救治疗效果，增加的血流灌注与内源性VEGF表达增强相关。相比之下，VEGF165过表达在第1天比基线水平高5倍，也能强烈诱导肌肉中的内源性VEGF，导致肢体加速截肢且血流灌注未恢复。有趣的是，接受VEGF165或FGF-2治疗的缺血肢体的存活骨骼肌显示出相似的血小板内皮细胞黏附分子-1阳性血管密度。然而，平滑肌肌动蛋白阳性细胞内衬表明新形成血管的成熟在VEGF处理的肌肉中受到显著干扰。此外，FGF-2的治疗效果在体内被抗VEGF中和抗体完全消除，因此表明内源性VEGF确实有助于FGF-2的作用。这些结果表明，VEGF是必要的，但应精细调节以降低其表达来治疗缺血肢体。FGF-2的治疗效果与内源性VEGF协同的血管生成作用相关，为治疗性血管生成提供了重要见解。
